Method and apparatus for testing the permeability of fibrous material



F. 1'. CARSON METHOD AND APPARATUS FOR TESTING THE PERMEABILITY OF FIBROUS MATERIAL Filed Dec. 17, 1923 glwum H01 Freder/kb4 7. Carson.

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. Application an December 17, 1923. Burial menace.

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To all whom it may concern: Be it known that I, Fnnnnnrcn T. CA3:-

son, a citizen ofthe United States, resid- 5, have invented 'a certain .new' and useful ing at Washington, District "of'Columbia,

Method and Apparatus. for Testing the Permeability of Fibrous Material, of which the following is a specification.

. The invention; more I particularly 'relates to a method and apparatus whereby the'sizr 'ing 'qualiti'e's and'charact'eristics-of fibrous material may be-definitely determined. y The object of the invention is to'provide "a method and ,apparatuswhereby the physical property 0 fibrous. sheet material to' curl-when subjected tomoisture, may bei the details description to follow.

.- which is its 'tendency surface of water to curl up into a cylindriaxis for the purpose of testing of slzing'of the paper or the like,

My invention more particularly relates to the use oflaphysic'al property of a fibrous material 'su'clifas sized 1paper or the like en floated on. the

cal form with the machine direction as an the degree Sizing-is that property'imparted to paper by the vintroduction of various water resisting substances into the pulp the course of'manufacture of the pa r.

" Sizefastness or sizing qualit isth'e.

' result of the addition of these various sub stances and is that quality of paper by vir- We of which it is capable ofi esis'ting to a greater or less degree the absorption of ink, 7: water or other hquids having no solvent;

action upon the sizing in the paper. It is a matter of common knowledge among those who have had experience in the testing of 'aper that the aniountfiof sizing materials mtroduced in a spot does. not necessaril Y give'any definite idea of the degree to whic v the paper will resist theabsorption of ink or other. liquids; 'As each particular fuse -.-of papermust have a definite absorption V value','-it is-evident that a method and means :for directly determining this yalue is ofgmat jgmortance. I c

The various-methods used heretofore to determine 'this value havefbeen foundv unsatisfactory. The various modifications of the well known fiotationtest, which consistsin noting'the time required for a liquid to penetrate the sheet asjudged by the depth of'color produced 'by mt'eracting'solutlons' pplied to opposite sides of-the test sama p es, are open to serious criticism and objecsufllciently-definite tovbe reli upon as a criterion of the state of penetration.

.tions.- There 18 no end-point or henomenon i Ink stroke tests in thehands of an experi-' sensed observer will. differentiate between different kind of paper In my 'methodhereinafter described the personal element in the test is eliminated and consequently a more uniform and accurate value of absor tion is obtained.

n the drawings, which show by way illustration one embodiment of the invention-.-

Figure 1, is a front view of partly diagrammatic. I Figure 2 isa. fr enta-ry Ian. view showing the test samp e, spring c ip holder, and ad ustable cover plate. g I v Figure 3 is a side view"of the apparatus with the-upperv parts removed showing a ertain current modit the apparatus,

vertical section alongthe line 3-3 of the Y inany convenient manner-,onthe base said reservoir being constructed in an'yisul manner and having a side wal12 regi al-i I 3:reservou'Ii is? upp ted 'at. -':=10 ie" lower than its opposite side "m convenient place above the main reservoir 1 and has an ap rture 7 in itsbase through which protrudes a needle valve 6. This follower plate 14 when the parts are in the. position shown by the broken lines in "alve 6 is supported on a float 8 which is disposed upon liquid4 in the main reser- V011.

A test-sample holding-device 10 is provided and adapted to grasp and hold a sample fibrous sheet 9. This device is provided with a spring-actuated clip 9 to hold the test-sample. This holding device is mounted on a cover plate 12 by a friction bolt 11 in such a manner as to permit of a slight 'rocking motion of said holding device. A fol lower plate 14 is pivotally secured to a base 16 by means of hinges 15-15. .Cover plate 12 is adjustably secured to follower plate 14 by means of a bolt 13, said bolt extending through a slot13 in the follower plate 14.

A bell crank lever 17 is pivotally secured to base 16 by a hinge 18 one arm 37 terminating in a thumb rest 17, the other arm 38 terminating in projection 20. Arm 38 of bell crank lever 17 is designed to Contact with astep 27 of the projection 19 on the Fi ire 1.

. watch 23; is suitably mounted, and a stem 22 of the watch is adapted to be engagedby a -stem extension or rod 21,, said rod being supported for longitudinal movement by an upright 25 and one end of'a bell crank lever 30. If desired, the rod 21 may be inte al with the stem 22. Suitable apertures are provided in the supports to permit the movement-of the stem extension 21.

On the free end of the upright 25 is se-J cured a retaining resilient member 26 which engages a step 27 of pro ection 19 on the follower plate 14, the function of the member 26 being to hold the follower plate 14 an parts attached thereto in operative position when the projection 19 of the follower; plate 14 is not in contact with the bell crank lever arm 38. A further function of the resilient member 26 is to arrest the motion of the follower plate 14 by contact with the upper edge of step 27 in the above described movement of follower plate '14 to operative position.

A yielding member 24 attached to base plate 16 is provided to disengage the contact relation of projection 20 'with the bell crank arm 30 when it operates to reset the'stop watch. It is obvious that these ele: ments depress stem 22 and permit the watch hand or indicating element to return to zero position.

A cover plate 35 is provided. for protecttiming device which may be a stop ing the liquid in the reservoir when the paper-test sample 9 is not in contact therewith, said plate being pivotally mounted at 36 to base 16. Attached to the cover plate 35 at pivot 36 is a crank'34,"the'movement of which is controlled by a link 32 fastened to follower plate 14 at 33, the function of said crank 34 being to actuate the move ment of the cover plate '35 when the follower plate 14 is moved to the position shown in dotted lines in Figure 1.

A background 28 is mountedto extend above the mam reservoir 1 against WhlCh the proportionatecurlingof the paper may tested on the device may be recorded as of comparative values, scale. v 1

In operating the device herein described the fibrous material to be tested is preferdetermined by such ably cut in a triangular form, the base portion of which is inserted in the spring clip 9. The clip 9 is so adjusted that a certain and predetermined portion of the under side of the paper comes in contact with the surface of the liquid in the main reservoir leaving the remainder untouched by For difi'erent grades of paper it is desirable to wet a larger or smaller area as the .case

may be, and the adjustable cover plate '12 is provided for this purpose, the means to adthe liquid.

just which 'has been previously described. a

The surface of the liquid in the reservoir 1 stands slightly above its lower wall 2 pre sentingr a rounded surface or meniscus con-\ vex upward. and it always remains at the" same level by reason of the automatic influx of fluid from the auxiliary reservoir The purpose of. this arrangement. is to wet but a given portion of the-test sample 9 so that the dry portion orthe upper part of the triangle, which acts as a pointer, will he carried across the field of vision (for excurling ofjhc wetted portion.-

At the instant the paper is placed in contact with the fluid in the reservoir 1, the

ample before the background 28) by the I projection 20 on the .bellcrank arm 17 J moves the stem extension 21 of the stop watch forward and this stem extension dc, presses the stem22 and sets .the stop watch 111 motion.

In the ordinary operation ofa stop watch the stem is depressed and the pressure '1-m;,

mediately released. In my device the for-'- ward movement of the bell crank lever'117 depresses the stem of the stop watch, as described. and to automatically relieve the pressure on the stem. the spring 24 is provided which moves the' arm 37 of the bell crank lever uprrard which obviousli moves the other arm 38 of the bell era-n lever backward and out of contact relation with. tl-iestcna extension. Whenthisarm is moved rive-y it is evident that it Will be taken out et-contact relation yvith the pro- J jection 19 of thofollower plate 14,.and the retaining spring member 26 is-provided for holding the followeraplate in the last named position,- said spring engaging with the projection-19- of-- the" follower plate. for this purpose;

When that portion the sample which is in contact with the liquid becomes sufiici-ontly moistened,{-said portion will curl fund th'us'swing upwardly the free end pertion S oi the sumpie; The curlingof the paper. is observed against the dotted oaclc' ground"28 and the momentthe point S of tho test sample 9 comes to rest, the bell crank arm 17 is depressed by its thumb rest 17, stopped.

The grades of paper to which this method is applicable range from a good news print to the finest bonds. The obvious advantage of this method is that definite and dependable data is-secured from Whicha numerical mine for therclative sizing quality of paper extent the personal element in its operation.

I so

can be compiled; Thev apparatus is simple in construction, )eqlllllng a minimum of a time for a test, and eliminating-to a great i To remove the test sample from the surface of the liquid the arm 37 of the bell crank lever 17 is raised and the projection 20 of the bell crank lever 17 comes in ,con-

tact with the projection 19 of the follower plate and the parts are returned to the origiin through which the operator may observe the operation. A thermonieter and-a h grometer '(not shown) may also be held in some suitable manner by the cabinet for the obvious purpose of making corrections for temperature and humidity. v y

. The-inven on described herein inay'bo used by the Government, or any of its'-of ficers or" employees in the prosecution of Work for-the Government, or by any other person in. the employ of the United States, without payment ofjany royalty thereon.

What I claim is- 1. The method of. determining the perwhereby the timing device is plate 35.

be covered with jmaterial :whereby the sizing q Ineability of fibrousmaterial, which con-' slsts' in bringing a of one end of'a strip of .fibrous material into contact with a fluid and simultaneously, starting. a timing mechanism, permitting the material to remainin contact withtlie fluid until a physical chan due to-an ab; sorption of the fluidat sai contacting-portion results in curling of the strip so as to cause the free. end thereof to assume-.1: pre-' determined maximum. position with relation to its initial position and finally by calculation from the elapsed time between arrival of the free end at its maximum physical posltlon and from known properties of the material, ascertaining the absorptive factor of the fibrous material.

ortion of one surface ,the time of fluid-contactand the time of 2;'The' method of determining the per mability of fibrous material, which consists 1n bringing a portionof onesurface of one end'of a strip of fibrous material.

into contact with a fluid and sin'iultaneously starting a timing mechanism, permittingthc' material to remain in contact with the fluid until a physical change due to an' absorption of the fluid at 'said contacting portion results in curling of the strip so as to-cause the free end thereof to assumea predetermined maximum position with relation to its initial position and finally dc- -te rminingthe'absorptivc factor of the fibrous materialby comparison of. the elapsed "time between the period of fluid contact and period of arriving at ltSJIltlXlllllllll physical position. with the time consumed fora standard sample to. undergo a like change.

3. A device for testing the permeability of a fibrous sheet. comprising means for bringing'ono face ofthe fibrou's'sheet into contact with a fluid, said meansincluding' a' pivoted material holder which is movable fr 0m oneposition ,wherein thematerial is not in contact with the fluid to a position wherein the material is in oontactwith the fluid, a-timing device, and means actuated;

. setting. in motion. the timing device simuh the material holderwhen moving from first na'med' position to the latter for taneousl =with the moistemng of the said sheet w erebyj the interval for its curling.

may be" ascertained.

4. An apparatus for determining the sizing quality of fibrous material comprising means for moistening a portion ofone face of the fibrous material whereby the move-- ment of the dry portion of said material is efi'ected :by -3t-l1e curling of the ino'istcned portion, a timing device and means actuated by the moistening means for: automatically setting in motion Ysaid timing device simu ta-neously with the moistening of the fibrous mlity of funotion oithg; :1.

fibrous materiahmay'fbe. determined use determined position.

5. An apparatus for determining the permeability of fibrous material comprising means for moistening the fibrous material whereby to effect the curling of the fibrous material, a timing device and means cooperating with the moistening means for'automatically setting in motion said timing device sin'iultaneously with the moistening of the fibrous material whereby the interval for the automatic influx of fluid from the auxiliary reservoir whereby the surface of the liquid in the main reservoiris maintained at a. constant level, and a timing device. for determining the time of curling of the fibrous material.

7. An apparatus for determining the permeability of fibrous material comprising means for contacting the surface of the fibrous material with the convex meniscus of a liquid whereby to effect the curling of the material, a reservoir 'for holding the liquid, and means for maintaining the convex meniscus at a constant level whereby the said fibrous material is held in contact with the surface of the liquid in a pre- -S. An apparatus for determining the pern'icability of fibrous material comprising a liquid reservoir in which one wall is of a difl'erent height from that of its opposite walls, whereby the liquid forms a convex meniscus, means for contacting a ortion of one face of fibrous material with the convex meniscus whereby a predetermined area of but one side of the fibrous material is vetted and which permits the unwetted free'end to move upwardly with the curling 10. In an apparatus for testing the perme- I ability of fibrous material including a reservoir for holding a liquid, a holder for saidfibrous material, a stop watch, means adjustably connected to the holder for moving the same solasto bring the material carried thereby into contact relation with said liquid whereby to effect the curling of said material, said means efiecting a pressure on the stem of said stop watch whereby to start its operation for the purpose of ascertaining the time of curling, and means whereby the said pressure effected by said mechanism is released.

FREDERICK T. caisson, 

